I started the trial and error method, using stated line on some, uplining some and going down 1-2 sizes on one. The common cents pretty much confirmed what trial and error arrived at. I don't believe it is fool proof but seems like a good check. Since there are no fly shops in my area everything is mail order so I will use it on new rods to give me a starting point.

It is a pain finding a way to get the rod level and secure. If there is any play in the grip the readings are not consistant, but if you clamp too tight the cork gets dented. Any tips out there other than stacking books? I'm thinking of some sort of padded u-clamp.